U.S. patent number 8,807,069 [Application Number 13/518,468] was granted by the patent office on 2014-08-19 for roll blade coating method and roll blade coating apparatus.
This patent grant is currently assigned to Ricoh Company, Ltd.. The grantee listed for this patent is Shuji Hanai, Tetsuya Hara, Nobuyuki Nagasawa, Satoshi Nakazawa. Invention is credited to Shuji Hanai, Tetsuya Hara, Nobuyuki Nagasawa, Satoshi Nakazawa.
United States Patent |
8,807,069 |
Hanai , et al. |
August 19, 2014 |
Roll blade coating method and roll blade coating apparatus
Abstract
A roll blade coating method including transferring an excessive
amount of a coating liquid onto a continuously running web, and
adjusting the excessive amount of the coating liquid to a desired
adhesion amount with a roll blade, wherein the roll blade is held
by a holding member for holding the roll blade, wherein the holding
member is pressed by a plurality of air cylinders each configured
to press the holding member, wherein the air cylinders are arranged
in a side of the holding member, which side is opposite to a side
where the holding member holds the roll blade, and wherein the air
cylinders can separately be adjusted in air pressure.
Inventors: |
Hanai; Shuji (Shizuoka,
JP), Nakazawa; Satoshi (Shizuoka, JP),
Nagasawa; Nobuyuki (Shizuoka, JP), Hara; Tetsuya
(Shizuoka, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hanai; Shuji
Nakazawa; Satoshi
Nagasawa; Nobuyuki
Hara; Tetsuya |
Shizuoka
Shizuoka
Shizuoka
Shizuoka |
N/A
N/A
N/A
N/A |
JP
JP
JP
JP |
|
|
Assignee: |
Ricoh Company, Ltd. (Tokyo,
JP)
|
Family
ID: |
45559599 |
Appl.
No.: |
13/518,468 |
Filed: |
July 29, 2011 |
PCT
Filed: |
July 29, 2011 |
PCT No.: |
PCT/JP2011/067923 |
371(c)(1),(2),(4) Date: |
June 22, 2012 |
PCT
Pub. No.: |
WO2012/018103 |
PCT
Pub. Date: |
February 09, 2012 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20130129925 A1 |
May 23, 2013 |
|
Foreign Application Priority Data
|
|
|
|
|
Aug 4, 2010 [JP] |
|
|
2010-174954 |
|
Current U.S.
Class: |
118/262; 118/414;
101/157; 101/169; 101/365; 162/281 |
Current CPC
Class: |
B05C
9/12 (20130101); B05C 11/025 (20130101); B05C
11/042 (20130101); D21H 25/12 (20130101); B05D
3/12 (20130101); B05D 2252/02 (20130101); B05D
1/40 (20130101) |
Current International
Class: |
B05C
11/02 (20060101) |
Field of
Search: |
;118/261,262,413,414
;162/281 ;15/256.52 ;101/157,169,365,120 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
61-57070 |
|
Dec 1986 |
|
JP |
|
4-22470 |
|
Jan 1992 |
|
JP |
|
5-15833 |
|
Jan 1993 |
|
JP |
|
2005-219054 |
|
Aug 2005 |
|
JP |
|
2005-279627 |
|
Oct 2005 |
|
JP |
|
2009-285596 |
|
Dec 2009 |
|
JP |
|
Other References
International Search Report and Written Opinion in
PCT/JP2011/067923, (Nov. 2011). cited by applicant.
|
Primary Examiner: Edwards; Laura
Attorney, Agent or Firm: Cooper & Dunham LLP
Claims
The invention claimed is:
1. A roll blade coating apparatus comprising: a roll blade
configured to adjust an excessive amount of a coating liquid on a
continuously running web to a desired adhesion amount; a holding
member for holding the roll blade; a plurality of air cylinders
each configured to press the holding member; and a plurality of
pressure regulators to regulate air pressure of the air cylinders,
wherein the air cylinders are arranged in a side of the holding
member, which side is opposite to a side where the holding member
holds the roll blade, wherein the air cylinders can separately be
adjusted in air pressure, and wherein the air cylinders directly
press the holding member.
2. The roll blade coating apparatus according to claim 1, wherein
each pressure regulator amongst the plurality of pressure
regulators is configured to adjust the air pressure of a
corresponding air cylinder to an air pressure lower than an average
air pressure of the other operating air cylinders.
3. The roll blade coating apparatus according to claim 1, wherein
each pressure regulator amongst the plurality of pressure
regulators is configured to gradually and simultaneously increase
the air pressure of a corresponding air cylinder to a desired air
pressure from the pressure lower than the desired air pressure.
4. The roll blade coating apparatus according to claim 1, further
comprising a display, wherein the air pressures of the air
cylinders are displayed on the display correspondingly to the
arrangement of the air cylinders.
Description
This application is a 371 of PCT/JP2011/067923 filed Jul. 29, 2001,
claiming priority of Japanese Patent application No. 2010-174954
filed on Aug. 4, 2010.
TECHNICAL FIELD
The present invention relates to a roll blade coating method and a
roll blade coating apparatus, which can suppress variations in
adhesion amount of a coating liquid constantly occurring on a web
(a base material made of a woven fabric or a nonwoven fabric) in
the width direction in roll blade coating, and obtain uniform
adhesion amount of the coating liquid on the web in the width
direction.
BACKGROUND ART
As a coating method in which an excessive amount of a coating
liquid is transferred onto a continuously running web (a base
material made of a woven fabric or a nonwoven fabric), and then
measured to a desired adhesion amount, for example, a Meyer bar
coating method, a blade coating method, a roll blade coating
method, an air knife coating method, and the like are known.
Of these, the roll blade coating method is widely used for coating
of various products, because a liquid having a high density can be
applied to form a thin film.
As shown in FIG. 1, the roll blade coating method is a method in
which a roll blade 31 is brought into pressure contact with a web
33 whose back surface is supported by a backup roll 32, so as to
remove an excessive amount of the coating liquid 34 transferred
onto the web 33. Moreover, as shown in FIG. 2, the roll blade 31 is
held by a holding member 35. A tubular air containing member 36
configured to press the holding member 35 is arranged in a side of
the holding member 35, which side is opposite to a side where the
roll blade 31 is held. This causes force which can bring the roll
blade 31 into press contact with the web 33.
FIG. 3 shows a conceptual diagram of a cross-section of A-A line in
FIG. 1 and a contact pressure between the roll blade 31 and the
backup roll 32 corresponding to the width direction position of the
cross-section.
The tubular air containing member 36 also applies force to a part
of the roll blade 31, which part is not in contact with the web 33
in the width direction. Thus, the contact pressure between the roll
blade 31 and the backup roll 32 in the vicinity of both ends of the
web 33 may be higher than the contact pressure therebetween at the
central part of the web 33 because of unevenness caused by the
thickness of the web 33. For this reason, in the conventional roll
blade coating, the adhesion amount of the coating liquid in the
vicinity of both ends of the web 33 becomes smaller than the
adhesion amount thereof at the central part of the web 33, and the
film thickness becomes uneven in the width direction.
To solve these problems, for example, in PTL 1 a roll blade coating
apparatus is proposed, which can uniformly apply a coating liquid
on a web in the width direction by providing a pressure detector
which converts pressure of the blade in each position of the width
direction into an electric signal.
However, in the roll blade coating apparatus described in PTL 1,
pressing force of the web against the roll blade in the width
direction cannot be adjusted by mechanical suppress strength, and
since the roll blade itself cannot be pressed, the adhesion amount
on the web in the width direction is hard to be effectively
adjusted.
Moreover, to solve the above-described problems, in PTL 2 a roll
blade coating method is proposed, in which an excessive amount of a
coating liquid is transferred onto a continuously running web, and
then a desired adhesion amount is adjusted with a roll blade so as
to coat the web with the coating liquid, and the method includes at
least a roll blade pressing step of pressing the roll blade via a
holder to a web whose back surface is supported by a backup roll,
wherein the roll blade is pressed with inclination of 15.degree. to
45.degree. in a travelling direction of the web with respect to a
normal direction of the backup roll, and a tubular air containing
chamber arranged to press the roll blade is divided into plural
chambers along the width direction of the roll blade, and an air
pressure in each of the plural tubular air containing chambers is
separately adjusted to obtain uniform pressing force of the roll
blade.
However, by the method disclosed in PTL 2, the tube cannot expand
to relatively wide in both sides of the divided portions of the
tube, and some parts of the tube cannot generate force to press the
roll blade. Thus, the tube cannot be finely divided and an
apparatus using the method cannot sufficiently function to solve
the problems.
CITATION LIST
Patent Literature
PTL 1 Japanese Patent Application Laid-Open (JP-A) No.
05-015833
PTL 2 Japanese Patent Application Laid-Open (JP-A) No.
2005-279627
SUMMARY OF INVENTION
Technical Problem
The present invention aims to provide a roll blade coating method
and a roll blade coating apparatus, which can suppress variations
in adhesion amount of a coating liquid constantly occurring on a
web in the width direction, specifically decrease in the adhesion
amount of the coating liquid in the vicinity of both ends of the
web in the width direction in roll blade coating, and obtain
uniform adhesion amount of the coating liquid on the web in the
width direction.
Solution to Problem
Means for solving the problems are as follows. <1> A roll
blade coating method including transferring an excessive amount of
a coating liquid onto a continuously running web, and adjusting the
excessive amount of the coating liquid to a desired adhesion amount
with a roll blade, wherein the roll blade is held by a holding
member for holding the roll blade, wherein the holding member is
pressed by a plurality of air cylinders each configured to press
the holding member, wherein the air cylinders are arranged in a
side of the holding member, which side is opposite to a side where
the holding member holds the roll blade, and wherein the air
cylinders can separately be adjusted in air pressure. <2> The
roll blade coating method according to <1>, wherein the air
pressure of each of the air cylinders arranged in the vicinity of
both ends of the web in the width direction is adjusted to an air
pressure lower than the average air pressure of the other operating
air cylinders. <3> The roll blade coating method according to
any one of <1> and <2>, wherein the roll blade has a
diameter of 8 mm to 15 mm. <4> The roll blade coating method
according to any one of <1> to <3>, wherein the air
cylinder has an outer diameter of 10 mm to 50 mm. <5> The
roll blade coating method according to any one of <1> to
<4>, wherein an arrangement pitch of the air cylinders is set
to satisfy the relation: outer diameter D of air cylinder
arrangement pitch<sum of 20 mm and outer diameter D of air
cylinder. <6> The roll blade coating method according to any
one of <1> to <5>, wherein a flat plate member is
provided between the holding member and the air cylinder such that
a gravity center of the flat plate member fits a shaft of the air
cylinder. <7> The roll blade coating method according to
<6>, wherein the flat plate member has a disc shape, and a
diameter smaller than the arrangement pitch of the air cylinders.
<8> The roll blade coating method according to any one of
<6> and <7>, wherein a part of the disc-shaped flat
plate member, which part is brought into contact with a rod of the
air cylinder, is formed into a concave spherical surface, and a
head of the rod of the air cylinder is formed into a convex
spherical surface. <9> A roll blade coating apparatus
including: a roll blade configured to adjust an excessive amount of
a coating liquid on a continuously running web to a desired
adhesion amount; a holding member for holding the roll blade; and a
plurality of air cylinders each configured to press the holding
member, wherein the air cylinders are arranged in a side of the
holding member, which side is opposite to a side where the holding
member holds the roll blade, and wherein the air cylinders can
separately be adjusted in air pressure. <10> The roll blade
coating apparatus according to <9>, wherein the air pressure
of each of the air cylinders arranged in the vicinity of both ends
of the web in the width direction is adjusted to an air pressure
lower than the average air pressure of the other operating air
cylinders. <11> The roll blade coating apparatus according to
any one of <9> and <10>, wherein the air pressures of
the air cylinders are gradually and simultaneously increased to
desired air pressures from pressures lower than the desired air
pressures. <12> The roll blade coating apparatus according to
any one of <9> to <11>, wherein the air pressures of
the air cylinders are displayed correspondingly to the arrangement
of the air cylinders.
Advantageous Effects of Invention
The present invention can solve the conventional various problems,
and achieve the objects, and can provide a roll blade coating
method and a roll blade coating apparatus, which can suppress
variations in adhesion amount of a coating liquid constantly
occurring on a web in the width direction, specifically decrease in
the adhesion amount of the coating liquid in the vicinity of both
ends of the web in the width direction in roll blade coating, and
obtain uniform adhesion amount of the coating liquid on the web in
the width direction.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram for explaining a conventional roll blade
coating method.
FIG. 2 is an exemplary schematic diagram of the conventional roll
blade coating apparatus used in FIG. 1.
FIG. 3 is a conceptual diagram of a cross-section of A-A line in
FIG. 1 and a contact pressure between a roll blade and a backup
roll corresponding to the width direction position of the
cross-section.
FIG. 4 is a diagram showing an example of a roll blade coating
apparatus of the present invention.
FIG. 5 is a schematic diagram showing an example of a roll blade
coating method using the roll blade coating apparatus of the
present invention.
FIG. 6 is a diagram showing the state of air cylinders and
arrangement thereof in the roll blade coating apparatus of the
present invention.
FIG. 7 is a diagram showing the state of a flat plate member in the
roll blade coating apparatus of the present invention.
FIG. 8 is a diagram showing the state of a flat plate member and a
rod of an air cylinder.
FIG. 9 is a diagram showing a method of adjusting air pressure.
FIG. 10A is a diagram showing an arrangement of the air cylinders
of the roll blade coating apparatus of the present invention, and
FIG. 10B is a diagram showing a display of a pressure of each of
the cylinders.
FIG. 11 is a diagram showing a method of adjusting air pressures of
four air cylinders which are arranged in the vicinity of each of
both ends of the web in the width direction in Examples 1 and
2.
FIG. 12 is a diagram showing a method of adjusting air pressures of
two air cylinders which are arranged in the vicinity of each of
both ends of the web in the width direction in Example 3.
DESCRIPTION OF EMBODIMENTS
(Roll Blade Coating Method and Roll Blade Coating Apparatus)
A roll blade coating method of the present invention includes
transferring an excessive amount of a coating liquid onto a
continuously running web, and adjusting the excessive amount of the
coating liquid to a desired adhesion amount with a roll blade,
wherein the roll blade is held by a holding member for holding the
roll blade, wherein the holding member is pressed by a plurality of
air cylinders each configured to press the holding member, wherein
the air cylinders are arranged in a side of the holding member,
which side is opposite to a side where the holding member holds the
roll blade, and wherein the air cylinders can separately be
adjusted in air pressure.
A roll blade coating apparatus includes a roll blade configured to
adjust an excessive amount of a coating liquid on a continuously
running web to a desired adhesion amount, a holding member for
holding the roll blade, and a plurality of air cylinders each
configured to press the holding member, wherein the air cylinders
are arranged in a side of the holding member, which side is
opposite to a side where the holding member holds the roll blade,
and wherein the air cylinders can separately be adjusted in air
pressure.
In the present invention, it is preferred that an air pressure of
each of the air cylinders arranged in the vicinity of both ends of
the web in the width direction be adjusted to an air pressure lower
than the average air pressure of the other operating air cylinders,
from the standpoint of achieving uniform adhesion amount of a
coating liquid on the web in the width direction.
In the specification, the vicinity of both ends of the web in the
width direction means areas each extending from each end to a
distance of 100 mm in both directions in the width direction. In
other words, the vicinity ranges from a position on the web at a
distance of 100 mm from the end to a position out of the web at a
distance of 100 mm from the end (the latter position is not on the
web).
As a method of adjusting an air pressure of each of air cylinders
arranged in the vicinity of both ends of the web in the width
direction to an air pressure lower than the average air pressure of
the other operating air cylinders, there is a method of adjusting
an air pressure using a regulator.
The degree of adjustment of the air pressure of each of the air
cylinders arranged in the vicinity of both ends of the web in the
width direction to an air pressure lower than the average air
pressure of the other operating air cylinders is not particularly
limited and may be appropriately selected depending on the intended
purpose.
The average air pressure of the air cylinders other than those
arranged in the vicinity of both ends of the web in the width
direction is not particularly limited and may be appropriately
adjusted depending on the intended purpose. It is preferably 0.13
MPa to 0.28 MPa.
The structure, size (width, length), and material, etc. of the roll
blade are not particularly limited and may be appropriately
selected depending on the intended purpose.
The shape, structure, size (width, length), and material, etc. of
the backup roll are not particularly limited and may be
appropriately selected depending on the intended purpose. For
example, as to the shape, a cylindrical shape is preferable. The
outer periphery of the backup roll is preferably coated with an
elastic body. Examples of the elastic body include a natural
rubber, a synthesis rubber, a resin, and a thermoplastic
elastomer.
The shape, structure, size (width, length), and material, etc. of
the web are not particularly limited and may be appropriately
selected depending on the intended purpose. Examples of the web
include various base materials. Examples of the material of the web
include paper, plastics, metals, and woods. Examples of the shape
of the web include a sheet shape, a band shape, and a roll
shape.
The shape, structure, size (width, length), and material, etc. of
the holder are not particularly limited and may be appropriately
selected depending on the intended purpose. Examples of the
material of the holder include rubbers, plastics, and metals.
Here, FIG. 4 is a diagram showing an example of a roll blade
coating apparatus of the present invention.
The roll blade coating apparatus of the present invention is a roll
blade coating apparatus using a method including transferring an
excessive amount of a coating liquid onto a continuously running
web (a base material made of a woven fabric or a nonwoven fabric),
and adjusting the excessive amount of the coating liquid to a
desired adhesion amount with a roll blade. The web runs at high
speed to improve productivity. Thus, a roll blade coating apparatus
1 of the present invention includes a roll blade 11 for measuring a
coating liquid, a holding member 14 for holding the roll blade 11,
in a back surface of the roll blade 11 a plurality of air cylinders
16 for uniformly pressing the holding member 14 against a web 13,
and a holder 23 for holding the air cylinders 16.
Moreover, a tube 17 for supplying air pressure is connected to the
air cylinder 16, in the tube 17, a pressure regulator 19 for
reducing pressure of a common tube 18 to a certain pressure is
provided.
FIG. 5 is a schematic diagram showing an example of a roll blade
coating method using the roll blade coating apparatus of the
present invention.
The roll blade 11 of the roll blade coating apparatus 1 of the
present invention is held by the holding member 14, and an air
cylinder 16 pressing the holding member 14 is arranged in a side of
the holding member 14 which side is opposite to a side where the
roll blade 11 is held.
The roll blade 11 supported by the air cylinder 16 is brought into
contact with the web 13 which is running while held by a backup
roll 12, and the air cylinder 16 is appropriately set to remove the
excessive amount of the coating liquid, to thereby obtain a desired
adhesion amount of the coating liquid on the web 13.
As shown in FIG. 4, in the roll blade coating apparatus 1 of the
present invention, a plurality of the air cylinders 16 configured
to press the holding member 14 are arranged in a side of the
holding member 14, which side is opposite to a side where the roll
blade 11 is held. With the plurality of the air cylinders 16,
pressing force against the web 13 is appropriately set, and
pressing force in the width direction is adjusted to suppress
deformation of the roll blade 11 in the width direction. Therefore,
the coating liquid can be applied in a desired, uniform adhesion
amount in the width direction on the web 13, to form a film having
a uniform thickness.
Moreover, in the roll blade coating apparatus of the present
invention, the diameter of the roll blade is selected from the
range of 8 mm to 15 mm.
Even though the roll blade coating apparatus 1 shown in FIG. 4 is
used, as shown in FIG. 3 the contact pressure in the vicinity of
both ends of the web in the width direction increases.
However, when a pressing force of the roll blade 11 against the web
13 increases at both ends, the air pressure of the air cylinder 16
with respect to the part where the pressing force increases can be
adjusted by appropriately reducing pressure using the pressure
regulator 19, to thereby adjust the pressing force. Thus, uniform
adhesion amount in the width direction can be obtained.
At that time, the diameter of the roll blade 11 is selected within
the range of 8 mm to 15 mm. When the diameter of the roll blade 11
is smaller than 8 mm, the force of the holding member 14 for
holding the roll blade 11 is not sufficient, dropping out of the
roll blade 11 during coating may easily occur. On the other hand,
when the diameter of the roll blade 11 is larger than 15 mm, there
increases a possibility that so-called bead streaks, which are
small pitch streaks, are generated all over the surface, and
rigidity of the roll blade 11 increases. Thus, even though the air
pressure of the air cylinder 16 is minutely adjusted in the width
direction, the pressing force of the roll blade 11 against the web
13 in the width direction becomes less effective, and it becomes
difficult to finely adjust adhesion amount of the coating
liquid.
FIG. 6 is a diagram showing the state of air cylinders and
arrangement thereof in the roll blade coating apparatus of the
present invention.
In the roll blade coating apparatus 1 of the present invention, the
outer diameter D of the air cylinder 16 is selected from the range
of 10 mm to 50 mm, with preference being given to 20 mm to 30
mm.
When the outer diameter D of the air cylinder 16 is smaller than 10
mm, even though a large number of air cylinders 16 are arranged, it
is necessary to set an air pressure fed to the air cylinder 16 to
relatively high.
Thus, when the air cylinder 16 is operated at high air pressure,
troubles easily occur in various parts. There causes a problem that
in the case where a large number of the air cylinders 16 are
required, the cost of devices including the pressure regulators 19
increases.
When the outer diameter D of the air cylinder 16 is larger than 50
mm, an area to be pressed by one of the air cylinders 16 increases,
and the pressing force in the width direction cannot be finely
adjusted.
In the roll blade coating apparatus 1 of the present invention, as
shown in FIG. 6, an arrangement pitch Y between the air cylinders
16 is represented by the following relation: the outer diameter D
of air cylinder 16.ltoreq.arrangement pitch<sum of 20 mm and the
outer diameter D of air cylinder 16. Moreover, the arrangement
pitch Y is preferably represented by the following relation: the
outer diameter D of air cylinder 16.ltoreq.arrangement pitch<sum
of 10 mm and the outer diameter D of air cylinder 16.
When the arrangement pitch Y is equal to or larger than sum of 20
mm and the outer diameter D of the air cylinder 16, it is necessary
to set an air pressure fed to the air cylinder 16 higher than that
when the air cylinders 16 are densely arranged. When the air
cylinder 16 is operated at high air pressure, troubles easily occur
in various parts, and moreover an area to be pressed by one of the
air cylinders 16 increases, and the pressing force in the width
direction cannot be finely adjusted.
Therefore, by setting the arrangement pitch Y to a value smaller
than the sum of 20 mm and the outer diameter D of the air cylinder
16, preferably a value smaller than the sum of 10 mm and the outer
diameter D of the air cylinder 16, a width of the part to be
pressed by one of the air cylinders 16 becomes appropriate, and the
pressing force in the width direction can be finely adjusted.
Note that each air cylinder 16 is mainly consisting of a cylinder
and a piston, and it is preferred that the diameter of the piston
be as large as possible, and that the inner diameter of the air
cylinder, i.e., the diameter of the cylinder be as large as
possible. Thus, the thickness of the air cylinder is made as thin
as possible in consideration of the pressure applied to the piston,
the cylinder and the like.
FIG. 7 is a diagram showing the state of a flat plate member in the
roll blade coating apparatus of the present invention.
In the roll blade coating apparatus 1 of the present invention, a
flat plate member 20 is provided between the holding member 14 for
holding the roll blade 11 and the air cylinder 16 such that a
gravity center of the flat plate member 20 fits a shaft of the air
cylinder 16. This flat plate member 20 allows air pressure applied
by a rod 21 of the air cylinder 16 to uniformly apply through the
holding member 14 in the width direction.
The holding member 14 somewhat changes its shape by application of
the pressing force. Even though the holding member 14 is deformed,
the flat plate member 20 is fastened to the rod 21 with allowance,
so that the flat plate member 20 comes into close contact with the
holding member 14. Consequently, the air pressure can be uniformly
applied through the holding member 14 in the width direction so as
to cancel the deformation of the holding member 14.
Moreover, since the flat plate member 20 is formed into a disc
shape, even though the flat plate member 20 is rotated or inclined
on the rod 21, it is possible to prevent the flat plate member 20
from being in contact with and interference to an adjacent flat
plate member 20. As a result, it is not necessary to form a large
space between the flat plate members 20, and the diameter of the
flat plate member 20 can be set slightly smaller than the
arrangement pitch Y between the air cylinders 16.
Moreover, the flat plate members 20 can minimize an area of the
holding member 14 for the roll blade 11, to which area the air
pressure cannot be applied by the air cylinder 16, thus the
pressing force in the width direction can be more uniformly
applied.
FIG. 8 is a diagram showing the state of a flat plate member and a
rod of an air cylinder.
A part of the flat plate member 20, which part is brought into
contact with the rod 21 of the air cylinder 16 is formed into a
downward-facing concave spherical surface in FIG. 8, and a head of
the rod 21 of the air cylinder 16 is formed into a convex spherical
surface in FIG. 8, so as to stabilize the contact between the flat
plate member 20 and the rod 21. This increases flexibility of the
contact between the flat plate member 20 and the rod 21. Therefore,
the close contact between the flat plate member 20 and the holding
member 14 for the roll blade 11 is more easily secured, and the
uniformity of the pressing force in the width direction can be more
improved.
FIG. 9 is a diagram showing a method of adjusting air pressure.
While the roll blade coating apparatus 1 of the present invention
performs coating using a main pressure regulator 22 an air pressure
P0 of the common tube 18 is set higher than certain air pressures
P1, P2, and P3, etc. adjusted in and transmitted through the
pressure regulators 19.
At the beginning of the coating with the roll blade coating
apparatus 1 of the present invention, in order to avoid the web 13
from fracturing, it is necessary to gradually increase a pressing
force of the roll blade 11 against the web 13 to a certain value.
Thus, in the roll blade coating apparatus 1 of the present
invention, the coating is started with setting the air pressures
P1, P2, and P3, etc. to pressures lower than the certain values,
followed by simultaneously increasing the air pressures to
respective certain air pressures P1, P2, and P3, etc.
The air pressure PO of the common tube 18 is set to an air pressure
for performing continuous coating using the main pressure regulator
22.
Next, using the pressure regulators 19, the air pressures P1, P2,
and P3, etc. are adjusted to certain values.
Moreover, using the main regulator 12, by reducing the air pressure
P0 to an air pressure lower than the air pressure for performing
continuous coating with maintaining the setting of the pressure
regulator 19, the air pressures P1, P2, and P3, etc. can also be
reduced, and the roll blade coating apparatus 1 is ready for
starting the coating.
At the beginning of the coating, the roll blade 11 is pressed
against the web 3 by applying the air pressure P0 which is lower
than the air pressure for performing continuous coating, and the
air pressure P0 is increased to the air pressure for performing
continuous coating, so as to achieve the start of the coating with
avoiding the web 3 from fracturing.
FIG. 10A is a diagram showing an arrangement of the air cylinders
of the roll blade coating apparatus of the present invention, and
FIG. 10B is a diagram showing a display of a pressure of each of
the cylinders.
A plurality of the air cylinders 16 are arranged with respect to
the width direction of the web 13 and the roll blade 11.
It may be required to finely adjust the air pressure of each of the
air cylinders 16 during coating. In order to easily adjust the air
pressure of each of the air cylinders 16, the air pressure of each
of the air cylinders 16 is displayed, to thereby secure fine
adjustment of each air pressure.
EXAMPLES
Hereinafter, Examples of the present invention will be specifically
described, however, the present invention is not limited to these
disclosed Examples.
Example 1
Using the roll blade coating apparatus of the present application
shown in FIG. 4, coating was performed under the following
conditions and while the adhesion amount of a coating liquid on a
web in the width direction was confirmed using an on-line adhesion
amount meter, the air pressure of each air cylinder was adjusted to
minimize deviation in the adhesion amount thereof on the web in the
width direction.
Specifically, as shown in FIG. 11, the pressures of four air
cylinders 16 in the vicinity of each of the both ends of the web
were reduced in 4 steps so as to be reduced in each step by 15%
with respect to the average air pressure (100%) of the other 56
operating air cylinders. The air cylinders were arranged in such a
manner that the edge of the web 13 was located substantially on the
middle of the four air cylinders 16 in the width direction (X in
FIG. 11).
Finally, the minimum deviation which could be adjusted was 3.6%.
(1) Coating base (web): woodfree paper having a basis weight of 62
g/m.sup.2, a thickness of 70 .mu.m, and a width of 1,560 mm (2)
Coating liquid: 10% by mass of aqueous polyvinyl alcohol (PVA)
solution (3) Coating rate: 400 m/min (4) Outer diameter of roll
blade: 12 mm (5) Length of roll blade: 2,300 mm (6) Outer diameter
of air cylinder: 20 mm (7) Arrangement pitch of cylinders: 26 mm
(8) Number of arranged cylinder: 80 Number of operating cylinder:
64
The deviation in adhesion amount of the coating liquid on the web
in the width direction was obtained by the following Equation (1).
Deviation in adhesion amount of a coating liquid in the width
direction (%)={(maximum adhesion amount (g/m.sup.2)-minimum
adhesion amount (g/m.sup.2)/average adhesion amount
(g/m.sup.2)).times.100 Equation (1)
Example 2
Using a roll blade coating apparatus of the present invention, in
which a part of the disc-shaped flat plate member 20, which part is
brought into contact with the rod 21 of the air cylinder 16 is
formed into a downward-facing concave spherical surface, and a head
of the rod 21 of the air cylinder 16 is formed into a convex
spherical surface shown in FIGS. 7 and 8, coating was performed
under the following conditions and while the adhesion amount of a
coating liquid on a web in the width direction was confirmed using
the on-line adhesion amount meter, the air pressure of each air
cylinder was adjusted to minimize deviation in the adhesion amount
thereof on the web in the width direction.
Specifically, as shown in FIG. 11, the pressures of four air
cylinders 16 in the vicinity of each of the both ends of the web
were reduced in 4 steps so as to be reduced in each step by 15%
with respect to the average air pressure (100%) of the other 56
operating air cylinders. The air cylinders were arranged in such a
manner that the edge of the web 13 was located substantially on the
middle of the four air cylinders 16 in the width direction (X in
FIG. 11).
Finally, the minimum deviation which could be adjusted was 3.1%.
(1) Coating base (web): woodfree paper having a basis weight of 62
g/m.sup.2, a thickness of 70 .mu.m, and a width of 1,560 mm (2)
Coating liquid: 10% by mass of aqueous polyvinyl alcohol (PVA)
solution (3) Coating rate: 400 m/min (4) Outer diameter of roll
blade: 12 mm (5) Length of roll blade: 2,300 mm (6) Outer diameter
of air cylinder: 20 mm (7) Arrangement pitch of cylinders: 26 mm
(8) Number of arranged cylinder: 80 Number of operating cylinder:
64 (9) Diameter of disc: 25 mm
Example 3
The deviation in adhesion amount of a coating liquid on a web in
the width direction was minimized in the same manner as in Example
1, except that, as shown in FIG. 12, the pressures of two air
cylinders 16 in the vicinity of each of the both ends of the web
were reduced in 2 steps so as to be reduced in each step by 15%
with respect to the average air pressure (100%) of the other 58
operating air cylinders. The air cylinders 16 were arranged in such
a manner that the edge of the web 13 was located substantially on
the middle of the two air cylinders 16 in the width direction (X in
FIG. 12).
The number of arranged cylinder: 80
The number of operating cylinder: 62
Finally, the minimum deviation which could be adjusted was
3.9%.
Comparative Example 1
Using a conventional roll blade coating apparatus, as shown in FIG.
3, coating was performed under the following conditions by means of
uniform pressing force using the tubular air containing member 36
and while the adhesion amount of a coating liquid on a web in the
width direction was confirmed using the on-line adhesion amount
meter, the air pressure inside the tubular air containing member
was adjusted so as to obtain the same adhesion amount thereof on
the web in the width direction as those in Examples 1 to 3.
There is a large difference in the adhesion amount between the
central part of the web in the width direction and ends of the web
in the width direction, and finally the minimum deviation which
could be adjusted was 8.7%. (1) Coating base (web): woodfree paper
having a basis weight of 62 g/m.sup.2 and a thickness of 70 .mu.m
(2) Coating liquid: 10% by mass of aqueous polyvinyl alcohol (PVA)
solution (3) Coating rate: 400 m/min (4) Outer diameter of roll
blade: 12 mm (5) Length of roll blade: 2,300 mm (6) Pressing width:
2,080 mm
According to the present invention, a coating liquid is applied in
a uniform adhesion amount on a web in the width direction, since in
the roll blade coating decrease in the adhesion amount of the
coating liquid on the web in the width direction in the vicinity of
both ends of the web can be corrected.
REFERENCE SIGNS LIST
1 roll blade coating apparatus
11 roll blade
12 backup roll
13 web
14 holding member
16 air cylinder
17 tube
18 common tube
19 pressure regulator
20 flat plate member
21 rod
22 main pressure regulator
23 holder
31 roll blade
32 backup roll
33 web
34 coating liquid
35 holding member
36 tubular air containing member
44 holder
A travelling direction of web
D outer diameter of air cylinder
Y arrangement pitch of air cylinders
P0 air pressure of common tube
P1, P2, P3 air pressure of air cylinder
* * * * *